PARIS
(AFP) – Researchers said they had pinpointed the biochemical pathway by which
cannabis causes memory loss in mice.News (Updated
August 9, 2009)
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ScienceDaily (Aug. 9,
2009) — Researchers at the Yerkes National Primate Research Center, Emory
University, believe conventional vaccine strategies should not be the only
avenue explored in the development of an effective AIDS vaccine. Based on
studying simian immunodeficiency viruses (SIVs) in African nonhuman primates,
they propose an additional new approach to the AIDS vaccine research agenda in a
commentary featured in the August issue of Nature Medicine. Their
recommendations outline specific research priorities and describe how each may
lead to a novel "out of the box" approach for developing an AIDS
vaccine.
"Developing an
effective AIDS vaccine has eluded scientists because the virus is tricky,"
says Guido Silvestri, MD, a Yerkes affiliate scientist and director of clinical
virology at the University of Pennsylvania School of Medicine and lead author of
the commentary. Silvestri, along with co-author James Else, DVM, associate
director for veterinary resources at Yerkes, writes, "Over 25 years after
the discovery of HIV as the etiological agent of AIDS, no effective vaccine for
the disease is available."
Most vaccines are based on
conventional strategies that work by triggering the body's immune system to
produce antibodies or killer T cells against the invading organism. The AIDS
virus, however, attacks the immune system, leaving it handicapped and unable to
mount an immune response. Therefore, conventionally designed AIDS vaccines that
have been clinically assessed to date have failed to protect vaccinated
individuals from HIV transmission or disease progression. This has been
demonstrated in two large-scale clinical trials aimed, respectively, at
eliciting HIV specific-antibodies to neutralize the virus and stimulating the
immune system's "killer T-cells" to target the virus.
"To put it another
way, a conventional vaccine strategy can be compared to using military might to
destroy an enemy (in this case, the virus). A less conventional strategy could
be to persuade the enemy not to attack you anymore," Silvestri explains.
Alternative strategies may include development of AIDS vaccines that make
infected individuals resistant to disease progression or resistant to the virus
by reducing the number of cells the virus can infect.
Silvestri and Else propose
that lessons learned from studying SIVs in their natural nonhuman primate hosts
may provide a path to an effective AIDS vaccine. SIVs are found exclusively in
African nonhuman primate species and represent the original source of human
immunodeficiency viruses (HIV-1 and HIV-2). More than 40 species of African
monkeys are infected in the wild with SIVs. Yet, virtually none with the
exception of chimpanzees progresses to HIV/AIDS or gets sick. Evolution has
enabled them to adapt to SIVs and co-exist peacefully with chronic infection.
"Nature is giving us
a message," says Silvestri. "Figure out how these monkeys can deal
with the virus, and then maybe you can get humans to do the same thing." In
particular, Silvestri notes additional studies of sooty managbeys – a
medium–sized African monkey – are critical for the AIDS vaccine effort and
understanding why SIV infection does not progress to HIV/AIDS. SIV-infected
sooty mangabeys develop a high viral load that does not increase their risk for
developing AIDS. Additionally, the SIV virus is rarely transmitted from mothers
to babies.
Silvestri also notes that
with its large colonies of uninfected and naturally infected sooty mangabeys,
"Yerkes has a unique resource for AIDS vaccine research and every effort
needs to be made to preserve and expand this colony of animals."
For nearly eight decades,
the
Within the fields of
microbiology, immunology, neuroscience and psychobiology, the center's research
programs are seeking ways to: develop vaccines for infectious and noninfectious
diseases, such as AIDS and Alzheimer's disease; treat cocaine addiction;
interpret brain activity through imaging; increase understanding of progressive
illnesses such as Parkinson's and Alzheimer's; unlock the secrets of memory;
determine behavioral effects of hormone replacement therapy; address vision
disorders; and advance knowledge about the evolutionary links between biology
and behavior.
Updated: Wednesday, 05 Aug
2009, 10:57 PM CDT
Published : Wednesday, 05 Aug 2009, 7:44 PM CDT
WFLD - Jeff Goldblatt
The majority of tests
there come back HIV positive, according to Executive Director Bruce Jackson.
“Out of all the diseases, HIV has the worst stigma. It needs to be gone.”
Since the start of the
HIV/AIDS epidemic in the late '80s, the disease has killed nearly 600,000
Americans, including 12,000 Chicagoans.
Medication can help
mitigate the symptoms, but health experts concur it’s a costly way to manage a
chronic, but now treatable, disease. That’s a significant factor as to why the
pharmaceutical industry has spent the better part of the last two decades trying
to develop a vaccine to wipe out HIV.
There hasn't been much
press coverage about this quest, because very few human trials have made it past
the early testing phase.
"Anyone who has
studied that arena knows there have been a number of failures," said Bob
McNally President and CEO of Geovax , a biotech firm based in
The first is a therapeutic
vaccine administered to ward off full-blown AIDS. The other is a preventative
vaccine given to uninfected patients, similar to the application of vaccines for
measles and rubella. When asked whether the vaccine might be the “magic
antidote,” McNally said, “We don't know that yet. I think that's what we're
trying to find out."
Fox Chicago has learned
Geovax, because of a large
There was a letter of
understanding signed June 15, 2009 by CEO of CCHHS, William Foley, Cook County
Board President Todd Stroger and County Commissioner John Daley, who also serves
as the President of the CORE Foundation .
The Foundation is the
public/private fundraising arm of the Ruth M. Rothstein CORE Center (CORE),
which is one of the nation's larger research and outpatient HIV facilities.
The preliminary proposal,
obtained exclusively by Fox Chicago, called for a small trial to take place at
CORE later this year on Geovax's therapeutic vaccine, with possible future tests
of the preventative vaccine there.
"Geovax really offers
us some hope,” said Stroger, who spearheaded the push to bring Geovax to CORE.
He says the vaccine trials
fit the mission of the federally funded center. "We see 1/3 of the AIDS
patients in
But barely a week later,
the CORE Foundation board made its own choice on this. In a letter obtained by
Fox Chicago, the board terminated its agreement with Geovax to start discussions
on vaccine trials. (See attached link)
"Everyone thinks
their kids look good, no one thinks their kids are ugly, right? Geovax, of
course, thinks it's great. But not the outside experts," said Dr. Robert
Weinstein, Chief Operating Officer of CORE.
Weinstein says CORE
consulted the nation's foremost medical experts in HIV/AIDS research before
turning down Geovax. He calls the vaccines medically risky, especially the
therapeutic version, which has yet to be tested in humans. "We didn't think
this was something we wanted to give to our paitent population. It doesnt mean
Geovax isn't a very good company, it doesn't mean their scientists aren't great
scientists, but based on our vetting with people who are not part of Geovax, we
got no encouragement to go ahead."
Geovax stands behind the
safety of its product, and notes that tests on monkeys at Emory's
And its preventative
vaccine is just one of a handful supported by the federally-backed HIV Vaccine
Trials Network to merit a second phase of human testing. “We just want to give
it a chance,” said McNally.
Stroger suspects it's
politics and not medicine that torpedoed Geovax at CORE.
Privately, supporters of
the partnership with CORE, said the hierarchy of the Cook County Health and
Hospitals System doesn't want to be upstaged by a progressive medical pitch from
President Stroger.
"Hopefully, we can
find a cure for AIDS, now sometimes things work out and you don't find what
you're looking for, but to dismiss it outright is almost criminal," said
Stroger.
For more than a decade,
the Stroger family controlled the hospital system, with the President's Office
responsible for oversight. The flagship of CCHHS, the
But that oversight changed
last year, when the
governing board for the
Health System.
CCHHS Spokesman, Lucio
Guerero, says it's Stroger's motives that warrant questioning, for trying to
force unproven science on the board during an election year. He says there are
17 HIV research trials currently underway at CORE.
"I trust the doctors,
the medical vetting of this, over any political gain," Guerero said.
"It's not about fundraising, it's not about who's right and who's wrong.
There's lives at stake."
Stroger says he's not
giving up hope on persuading CORE to partner up with Geovax. Fox Chicago learned
of a private meeting Wednesday on Geovax between a top aide to Stroger and a
high-level CCHHS official. But the CEO of Geovax said he doesn't want to be at
the center of a political power struggle, and that he's moving on to find
another clinic, preferably in Chicago, for his company’s vaccine trials.
Monday, August 3, 2009. A
new strain of the virus that causes AIDS has been discovered in a woman from the
African nation of
It differs from the three
known strains of human immunodeficiency virus and appears to be closely related
to a form of simian virus recently discovered in wild gorillas, researchers
report in Monday's edition of the journal Nature Medicine.
The finding
"highlights the continuing need to watch closely for the emergence for new
HIV variants, particularly in western central Africa," said the
researchers, led by Jean-Christophe Plantier of the University of Rouen in
France.
The three previously known
HIV strains are related to the simian virus that occurs in chimpanzees.
The most likely
explanation for the new find is gorilla-to-human transmission, Plantier's team
said. But, they added, they cannot rule out the possibility that the new strain
started in chimpanzees and moved into gorillas and then humans, or moved
directly from chimpanzees to both gorillas and humans.
The woman currently shows
no signs of AIDS and remains untreated, though she still carries the virus, the
researchers said. How widespread this strain is remains to be determined.
Researchers said it could be circulating unnoticed in
-- Associated Press
By
In recent years diseases
like HIV-AIDS and Ebola have been traced to chimpanzees, and a study being
released Tuesday shows that this is nothing new, according to Dr. Nathan D.
Wolfe, an author of the report in Proceedings of the National Academy of
Sciences.
"Malaria has been a
human disease as long as history," Wolfe, of
"It is now clear that
a new disease that successfully jumps from an animal to a human can last not
just for decades, but millennia or more," Wolfe said. "This makes the
task of stopping future disease spillovers from animals to humans vital, not
only for saving lives today, but for the health of people for many generations
to come."
According to the U.S.
Centers for Disease Control and Prevention, each year more than a million
people, mostly children, die of malaria worldwide.
Malaria is caused by a
parasite, Plasmodium falciparum, which is transmitted from person to person via
mosquitoes.
It was known that
chimpanzees could harbor a related parasite, Plasmodium reichenowi. The
researchers, led by Wolfe and Francisco Ayala of the
Conventional wisdom had
been that the two parasites diverged from a common origin, Wolfe said, but a
comparison of the two indicates that the human version more likely developed
from the chimpanzee type.
"We now know that
malaria, while at least thousands of years old, did not originate in humans but
rather was introduced into our species, presumably by the bite of a mosquito
that had previously fed on a chimpanzee."
Now, Wolfe said, the goal
is to learn more about the chimp parasites and try to figure out how they spread
to people.
The researchers said the
shift of the malaria parasite to humans could have taken place as long as 2
million to 3 million years ago, or as recently as 10,000 years ago.
A better understanding of
these chimp parasites might lead to improved treatments for malaria or even
development of a vaccine, Wolfe said, noting early smallpox vaccines were
developed from the related cowpox.
The research was funded by
the National Institutes of Health,
Mon Aug 3, 2:03 pm ET
WHITEHOUSE STATION, N.J.
– Merck & Co.'s head of vaccines, Margaret G. McGlynn, is retiring
effective Nov. 1, the drugmaker said Monday.
McGlynn, 49, has been
president of Merck's vaccines division since 2005 and, more recently, Merck
Vaccines and Infectious Diseases. Previously, she served as head of U.S. Human
Health, the company's marketing operation.
"She decided that now
was a good time to pursue many personal and professional aspirations,"
Merck spokeswoman Amy Rose said.
Rose said no replacement
has been named yet for McGlynn, who joined the company 26 years ago.
McGlynn helped oversee a
surge in new vaccine approvals the last few years that made the division
increasingly important financially to Merck. Those included the blockbuster
Gardasil, the first vaccine to prevent cervical and other sexually transmitted
cancers, and RotaTeq for rotavirus. Merck's HIV drug Isentress also was approved
during her tenure.
However, the division has
been plagued by manufacturing deficiencies cited by the Food and Drug
Administration, some dating back to spring 2007, that have reduced sales
significantly.
Vaccines against
Haemophilus influenza type B, shingles and a combination one against measles,
mumps, rubella and chickenpox called ProQuad either were recalled or production
was halted for long stretches. Zostavax, the shingles vaccine, just resumed
normal shipments in June, and ProQuad is still not available, although Merck
settles other vaccines that separately protect against the four childhood
illnesses, Merck noted in a regulatory filing Monday.
Until November, McGlynn
will continue to lead the business and keep her other leadership positions, the
company said. That includes helping plan for Merck's $41.1 billion acquisition
of partner drugmaker Schering-Plough Corp. of
Thu Aug 6, 8:30 am ET
PARIS (AFP) – Scientists
in the
The breakthrough should
help develop strategies for combating the virus with new anti-viral drugs, the
researchers said.
"We are beginning to
understand tricks the genome uses to help the virus escape detection by the
human host," said Kevin Weeks, a professor at the
Like the viruses that
cause influenza and hepatitis C, HIV carries its genetic information in
single-strand RNA rather than the double strand DNA found in all living
organisms and certain viruses.
This make is more
difficult to decode because, unlike DNA, RNA is able to fold itself into
intricate, three-dimensional patterns.
Earlier studies have
succeeded in modeling small regions of the HIV genome, which consists of two
strands each containing nearly 10,000 nucleotides, the basic molecular building
blocks of both DNA and RNA.
Using a new technique,
Weeks and colleagues produced images which, while lower in resolution, spanned a
much larger area.
The study, published in
the British journal Nature, should help scientists discover ways in which the
RNA genome determines the lifecycle of the HIV virus.
"One approach is to
change the RNA sequence and see if the virus notices," said Ronald
Swanstrom, a microbiologist at UNC and a co-author of the study.
"If it doesn't grow
as well when you disrupt the virus with mutations, then you know you've mutated
or affected something that was important to the virus," he said in a
statement.
Hashim Al-Hashimi of the
"Structural
biologists can now use this genomic map to judiciously zoom in on pieces of the
HIV-1 genome and determine architectural and functional principles at the atomic
level," he said.
AIDS first came to public
notice in 1981, when alert
It has since killed at
least 25 million people, and 33 million others are living with the disease or
the HIV virus, which destroys immune cells and exposes the body to opportunistic
disease.
by Marlowe Hood Marlowe
Hood Sun Aug 2, 11:19 pm ET
PARIS
(AFP) – Researchers said they had pinpointed the biochemical pathway by which
cannabis causes memory loss in mice.
The discovery could help
open the way to drugs that have marijuana's desired pain-killing properties but
without its amnesic side effects, according to the paper, published in the
journal Nature Neuroscience.
It has long been known
that cannabis produces memory loss by acting on the hippocampus, the region in
the brain that governs most of our cognitive functions.
But whether that impact
was long-term or lasted only during the drug's use, as well as how the drug
acted biochemically, has been intensely debated.
Rafael Maldonado and and
Andres Ozaita at
The scientists first
created a new measure of cognitive impairment so that they could easily assess
the impact of cannabis use on memory in normal mice.
Marijuana's active
ingredient, THC, acts on cannabinoid receptor neurons called CB1. While found in
several locations within the brain, there are two concentrations of CB1-type
cells in the hippocampus.
To explore how each of
these neural networks might affect memory loss, the researchers created two
groups of genetically modified mice, each missing the CB1 receptors in either of
the two regions.
The rodents were then
injected with doses of THC equivalent to "heavy use" of marijuana in
humans.
One of the groups reacted
in the well-known forgetful fashion when required to do memory tests.
The other mouse group --
whose CB1 had been removed from the so-called GABAergic neurons -- was
unaffected by the drug.
"Not only were the
behavioural effects abolished, the biochemical responses that are directly
responsible for the amnesic-like effect were abolished too," Maldonado said
in a phone interview.
This should make it
possible to develop a molecule that will produce cannabis' positive effect
without affecting the GABAergic brain cells that govern memory, he said by
phone.
The research also showed
that administering cannabis leads to a change in the way that proteins are
manufactured in the affected part of the brain.
"This is crucial,
because a change in protein synthesis means a long-term change, this is not
something that will just disappear the next day," he said.
Just how long memory might
be degraded is unknown, he added.
"These are not
permanent changes, even if they are long-term. People who are using cannabis
therapeutically should not be worried," he said.
Maldonado refused to give
an opinion about the impact for recreational users of marijuana, though.
Despite its ambiguous
legal status, marijuana is used in several countries, especially the
Unlike illegal marijuana,
so-called medical marijuana comes from an identified source in which levels of
THC are known and monitored.